Preparation method of semiconductor device

Abstract

The invention provides a preparation method of a semiconductor device, which comprises the following steps: providing a substrate, forming a gate structure on the substrate, and forming an active region and a drain region in the substrate at two sides of the gate structure; forming a first dielectric layer on the substrate, wherein the first dielectric layer covers the substrate and the gate structure; forming a top metal layer on the first dielectric layer, wherein the top metal layer is electrically connected with the gate structure, the source region and the drain region; conformally forming a second dielectric layer on the first dielectric layer and the top metal layer; etching partial thickness of the second dielectric layer above the top metal layer, carrying out a planarization process on the second dielectric layer, uniformizing the shape of the second dielectric layer through the etching process, and further improving the grinding speed of the second dielectric layer and the grinding precision of the second dielectric layer. The problems of plasma damage and electric leakage caused by free charges generated in the plasma deposition process collected by the top metal layer are avoided.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for preparing a semiconductor device. Background technique [0002] In the manufacturing process of semiconductor devices, it is usually necessary to deposit thin films on the substrate to form the desired device, such as depositing a metal film on the substrate as a metal layer, depositing a dielectric layer on the substrate, etc., in order to improve the structure of the deposited film Densification usually combines plasma process and chemical vapor deposition process, such as plasma enhanced chemical vapor deposition (PECVD) or high density plasma chemical vapor deposition (HDPCVD) for thin film deposition. [0003] The existing thin film deposition technology includes the following steps: placing the substrate on the electrostatic chuck in the deposition chamber; feeding the gas to be reacted into the deposition chamber, turning on the radio frequency sourc...

AI Technical Summary

Problems solved by technology

When the metal layer is formed, the metal layer will collect the free charges on the substrate and transfer a large amount of charges to the gate structure, forming a leakage current in the gate oxide layer under the gate structure. When the accumulated charges reach a certain amount , the leakage current will discharge in the gate oxide layer, causing plasma damage to the gate oxide layer, thereby reducing the breakdown resistance of semiconductor devices

And with the continuous reduction of the feature size of semiconductor devices in recent years, the thickness of the gate oxide layer is also continuously reduced, and the leakage phenomenon caused by plasma damage is more serious, and even causes the scrapping of the device

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